The White House said the actions were necessary to counter unfair competition from China’s state-led economy.
It said years of talks had failed to produce change. China said it was ready to retaliate with “necessary measures”.
Beijing also said it would “fight to the end” in any trade war with the US.
US stock markets closed lower on Thursday, as investors responded to the announcement.
The Dow Jones ended the day at 23,957.89, a fall of 2.9% or 724.42 points – making it the fifth biggest points fall ever.
The S&P 500 shed 2.5% or 68.24 points to 2,643.69, and the tech-heavy Nasdaq lost 2.4% or 178.61 points to finish at 7,166.68.
Signing a memo related to the sanctions, Mr Trump said the US and China were negotiating and he was looking for “reciprocal” trade terms for American companies.
He said the tariffs might be imposed on up to $60bn in Chinese goods – boosting the number from the roughly $50bn figure White House officials cited on Thursday morning during a briefing.
The tariffs follow an investigation of Chinese policies ordered by Mr Trump in August.
The White House said the review found a range of “unfair” practices in China, including restrictions on foreign ownership that pressured foreign companies into transferring technology.
The US is also exploring ways to limit Chinese investment in the US and will seek to bring complaints about unfair licensing terms to the World Trade Organization, officials said.
America’s top trade negotiator, Robert Lighthizer, said protecting US technology was critical to America’s economic future.
On Thursday, China’s commerce ministry said it was ready to retaliate against the new tariffs.
“China will not sit idly by and let its legitimate rights and interests be harmed, and will certainly take all necessary measures to resolutely defend its legitimate rights and interests,” it said in a statement.
The ministry also pointed to a ruling by the World Trade Organization (WTO) that found that Washington had not fully complied with a 2014 ruling against its anti-subsidy tariffs on Chinese products, including solar panels and wind towers.
China’s commerce ministry said the WTO ruling “proves that the US side has violated WTO rules” and “repeatedly abused trade remedy measures”.
“[This] has seriously damaged the fair and just nature of the international trade environment, and weakened the stability of the multilateral trading system.”
The WTO has also ruled against China’s trade practices. In January, the organisation said China must lower its tariffs on broiler chickens imported from the US.
If imposed as described, the tariffs could lead to higher costs for consumers, while retaliation would hit key sectors of the US economy including agriculture and aerospace, analysts say.
China was the third largest market for US exports in 2016 and among the biggest buyers of American soybeans, corn, pork and aircraft.
====BBC
